Ageratum houstonianum

Botanical Name: 
Ageratum houstonianum
Common Name: 
Floss flower, Blue weed

An annual plant often grown as bedding in gardens, it has ovate to triangular leaves 2-7cm long and most commonly blue flowers (although white, pink, or purple are available)

The flower heads are borne in dense corymbs. The flowers are threadlike leading to the common name floss flower.

It is native to Mexico and Central America, and is starting to become a problem weed in other areas.

It is toxic to grazing animals.

Ht: 0.3m to 1m


Cottage gardens, formal, fillers, for its long flowering period and flower colour.


by seed.